Six arguments low


Published on

Published in: Technology, Business
  • Be the first to comment

No Downloads
Total Views
On Slideshare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide

Six arguments low

  1. 1. Six Arguments for a Greener Diet
  2. 2. Six Arguments for a Greener DietHow a More Plant-Based Diet Could SaveYour Health and the EnvironmentCenter for Science in the Public Interest
  3. 3. Copyright © 2006 by Center for Science in the Public InterestFirst Printing, July 20062 4 6 8 10 9 7 5 3 1The Center for Science in the Public Interest (CSPI), founded in 1971, is a nonprofitorganization that conducts innovative education, research, and advocacy programsin the area of nutrition, food safety, environment, and alcoholic beverages. CSPIis supported by the 900,000 subscribers in the United States and Canada to itsNutrition Action Healthletter and by foundation grants.Center for Science in the Public Interest1875 Connecticut Avenue, NW, #300Washington, DC 20009Tel: 202-332-9110; fax: 202-265-4954Email:; Internet: www.cspinet.orgISBN 0-89329-049-1Visit CSPI’s Eating Green web site:
  4. 4. The Web of Animal-Based Foods and Problems Natural gas, ores Fertilizer Pesticides Air, soil & water Risks to pollution farmers & wildlife Irrigation water Ground- water depletion Antibiotics, hormones Animal feed Soil erosion Health & ecological risks GlobalAnimal warmingcruelty (methane) Meat, Manure dairy, eggs Soil Air Water Food Cancer Heart pollution pollution pollution poisoning disease
  5. 5. Eating Green: By the Numbers(All figures apply to the United States, except where noted, and are approximate. See text for sources.) Health3 years: how much longer vegetarian Seventh-day Adventists live than non-vegetarian Seventh-day Adventists4.9 servings: the servings of fruits and vegetables consumed daily, compared tothe recommended 5 to 1016 percent: the decreased mortality from heart disease associated with eatingone additional serving of fruits or vegetables each day24 percent: how much lower the rate of fatal heart attacks is in vegetarians com-pared to non-vegetarians25 percent: the proportion of food-poisoning deaths due to pathogens from ani-mals or their manure33 percent: the decrease in beef consumption since 197650 percent: how much less dietary fiber Americans consume than is recommended51 percent: the reduction in risk of heart attack for people eating nuts five ormore times per week compared to less than once a week90 percent: the proportion of chickens contaminated with Campylobacter bacteria100 percent: how much fattier meat is from a typical steer that’s fed grain ratherthan grass199 pounds: the combined amount of meat, poultry, and seafood produced perAmerican (2003)1,100: the mortalities due each year to foodborne illnesses linked to meat, poul-try, dairy, and egg products46,000: the number of illnesses due annually to antibiotic-resistant strains of Sal-monella and Campylobacter63,000: the number of deaths from coronary heart disease caused annually by thefat and cholesterol in meat, dairy, poultry, and eggs$7 billion: the annual medical and related costs of foodborne illnesses$37 billion: the annual cost of drugs to treat high blood pressure, heart disease,and diabetes$50 billion: the annual cost of coronary bypass operations and angioplasties
  6. 6. Environment1 pound: the amount of fertilizer needed to produce 3 pounds of cooked beef5 times as much: the irrigation water used to grow feed grains compared to fruitsand vegetables5 tons: the soil lost annually to erosion on an average acre of cropland7 pounds: the amount of corn needed to add 1 pound of weight to feedlot cattle(some of that weight gain is not edible meat)19 percent: the proportion of all methane, a greenhouse gas, emitted by cattleand other livestock41 percent: the share of irrigated land planted in livestock feed crops66 percent: the proportion of grain that ends up as livestock feed at home orabroad331: the number of odor-causing chemicals in hog manure4,500 gallons: the rain and irrigation water needed to produce a quarter-poundof raw beef8,500 square miles: the size of the “dead zone” created in the Gulf of Mexico byfertilizer runoff carried by the Mississippi from the upper Midwest33 million: the number of cars needed to produce the same level of global warm-ing as is caused by the methane gas emitted by livestock and their manure22 billion pounds: the amount of fertilizer used annually to grow feed grains forAmerican livestock3.3 trillion pounds: the amount of livestock manure produced annually17 trillion gallons: the amount of irrigation water used annually to produce feedfor U.S. livestock Animal Welfare0.5 square feet: the amount of space allotted to the average layer hen30: the number of chickens and turkeys consumed annually by the averageAmerican13,200: the number of chickens killed each hour in a modern slaughterhouse50,000: the number of broiler chickens in the largest growing sheds140 million: the number of cattle, pigs, and sheep slaughtered each year
  7. 7. ContentsAcknowledgments    iiiAbbreviations    vPreface: Greener Diets for a Healthier World    vii The ContextThe Fatted Steer    3 The Arguments#1. Less Chronic Disease and Better Overall Health    17#2. Less Foodborne Illness    59#3. Better Soil    73#4. More and Cleaner Water    87#5. Cleaner Air    103#6. Less Animal Suffering    113 Making ChangeChanging Your Own Diet    143Changing Government Policies    151
  8. 8. ii • Six Arguments for a Greener Diet Appendixes and NotesAppendix A. A Bestiary of Foodborne Pathogens    171Appendix B. Eating Green Internet Resources    177Notes    181Photo Credits    223Index    225
  9. 9. AcknowledgmentsT his book is a publication of the Center for Science in the Public Inter- est’s (CSPI’s) Eating Green project, which advocates a more plant- based diet to protect both health and the environment. Asher Wolfdrafted the chapters on foodborne illness, soil, water, air, and animal wel-fare; Reed Mangels wrote the chapter on chronic disease; and Michael F.Jacobson wrote several other chapters and edited the entire manuscript.Michael Kisielewski contributed valuable editing and research; MoiraDonahue, Judy Jacobs, Phyllis Machta, Tyler Martz, Jonathan Morgan, andCarol Touhey helped with proofreading and fact checking. Nita Congressprovided invaluable advice while she edited and designed the book. CSPI’sDebra Brink designed the cover and several graphic displays. Numerous experts in government, academe, and nonprofit organiza-tions generously provided data, advice, and reviews of entire chapters.Those people include Tamar Barlam, Aaron Blair, Navis Bermudez, Law-rence Cahoon, Winston Craig, Karen Florini, Tom Gegax, Noel Gollehon,Michael Greger, Robert Hadad, Ed Hopkins, Dennis Keeney, Ronald Lace-well, Alice Lichtenstein, Robbin Marks, Roy Moore, Mark Muller, FrenschNiegermeier, David Pimentel, Nancy Rabalais, Darryl Ray, Steven Roach,Bernard Rollin, Gail Rose, Joe Rudek, Daniel Rule, Frank Sacks, JenniferSass, Paul Shapiro, Parke Wilde, and George Wuerthner. In addition, CSPI iii
  10. 10. iv • Six Arguments for a Greener Dietstaffers Caroline Smith DeWaal, Bonnie Liebman, and David Schardtreviewed chapters and offered much useful advice. Notwithstanding allthat assistance, this book might still contain factual errors and inappropri-ate characterizations, for which the editor, Michael F. Jacobson, deservesthe dubious credit. Finally, we are grateful to John Robbins for writing hisground-breaking Diet for a New America, which helped inspire our work. CSPI extends its sincere gratitude to the Freed Foundation, Tom andMary Gegax, the Shared Earth Foundation, Lucy Waletzky, and the WallaceGenetic Foundation for their generous support of the Eating Green projectand the preparation of this book.
  11. 11. AbbreviationsAMR advanced meat recoveryBMI body mass indexBSE bovine spongiform encephalopathyCAFO concentrated animal feeding operationCDC Centers for Disease Control and PreventionCHIP Coronary Health Improvement ProjectCLA conjugated linoleic acidCRP Conservation Reserve ProgramCSPI Center for Science in the Public InterestDASH Dietary Approaches to Stop HypertensionDHA docosahexaenoic acidEDC endocrine-disrupting compoundEPA eicosapentaenoic acidEPA Environmental Protection AgencyEPIC European Prospective Investigation into Cancer and NutritionEQIP Environmental Quality Incentives ProgramEWG Environmental Working GroupFDA Food and Drug AdministrationHCA heterocyclic amineHDL high-density lipoprotein
  12. 12. vi • Six Arguments for a Greener DietLDL low-density lipoproteinPAH polycyclic aromatic hydrocarbonPBDE polybrominated diphenyl etherPCB polychlorinated biphenylPETA People for the Ethical Treatment of Animalsppm parts per millionrBST recombinant bovine somatotropinSDA Seventh-day AdventistUSDA U.S. Department of AgricultureUSGS U.S. Geological SurveyvCJD variant Creutzfeldt-Jakob diseaseVOC volatile organic compoundWIC Women, Infants, and Children
  13. 13. Preface:Greener Diets for a Healthier WorldA mericans eat what might be called an all-consuming diet. Together, we represent over 40 billion pounds of protoplasm that each day needs to be fed over 1 billion pounds and 1 trillion calories of food.Our agricultural system consumes enormous quantities of fuel, fertilizers,and pesticides to produce the grains, meat and poultry, and fruits and vege-tables that feed a nation of 300 million people. It consumes enormous tractsof land and quantities of water—not only for growing food for people, butalso for producing food for livestock. And ultimately it consumes the con-sumer: Diet-relateddiseases account forhundreds of thou-sands of prematuredeaths each year. Six Arguments for aGreener Diet analyzesthe multitudinous andfar-reaching effects oflivestock productionand consumption. Onthe health front, most vii
  14. 14. viii • Six Arguments for a Greener Dietconsumers probably know that the saturated fat and cholesterol in fattybeef and dairy products and eggs promote heart disease. Fewer people areaware that beef has been linked to colon cancer and milk to prostate cancer.Adding to the toll are the toxic chemicals, such as polychlorinated biphenyls(PCBs), that animals tend to accumulate in their muscle fat and milk. In all,animal foods may be responsible for 50,000 to 100,000 premature deathseach year. (Not surprisingly, vegetarians tend to be healthier than the restof us.) While heart disease and cancer generally take decades to develop,meat, poultry, and eggs are major causes of food poisoning, which showsup quickly. Over 1,000 people die each year from livestock-related food-borne illnesses caused by bacteria such as Salmonella and E. coli. In fact,many foodborne illnesses traced to fruits and vegetables actually are due toanimal manure that gets onto crops. Some foodborne germs are especiallyharmful because they defy the usual antibiotic treatment. Such antibioticresistance results, in part, from the feeding of small amounts of antibioticsto cattle, hogs, and poultry to fatten the animals faster or compensate for thedirty, crowded conditions in which they live. Consuming large quantities of animal products has inevitable envi-ronmental consequences. Beef cattle typically live out their last severalmonths in huge, densely populated feedlots. The 50,000 cattle that reside ina large feedlot at a given time produce as much manure as a city of severalmillion people. Not surprisingly, they create a stench that undermines thequality of life for everyone who lives or works nearby. Even grazing can beproblematic. In some parts of the West, cattle graze on ecologically sensitiveland, which can destroy normal vegetation. Industrial-scale hog productionrelies on pond-sized cesspools (euphemistically called lagoons by agribusi-ness) of manure. Stench aside, cesspools sometimes break open and pollutelocal streams and rivers. A high percentage of the grains and hay grown on our nation’s farmsfeeds animals, not humans. Producing the vast quantities of corn, soybeanmeal, alfalfa, and other ingredients of livestock feed consumes vast quanti-ties of natural resources and requires thousands of square miles of land.Much of the Midwest’s grasslands and forests have been replaced by grainfarms. In the arid West and Great Plains, large amounts of irrigation water,which might otherwise be used as drinking water or in more productivecommercial enterprises, are needed to produce feed grains. Although shift-ing to grass-fed beef would solve some of the environmental problems,as well as provide leaner meat, one serious problem would remain: Cattlenaturally emit methane, a potent greenhouse gas.
  15. 15. Preface: Greener Diets for a Healthier World • ix The chemical fertilizers that farmers use to help maximize grain pro-duction take a great deal of energy to produce, and they pollute waterwaysand drinking water. Because of all the fertilizer that washes down theMississippi River, the Gulf of Mexico has a poorly oxygenated “dead zone”the size of New Jersey. Using chemical pesticides to protect crops frominsects and other pests frequently results in those chemicals contaminat-ing drinking water in rural areas, as well as endangering farmworkers andwildlife. The small amounts that we consume when we eat both plant andanimal foods are unwelcome, if not demonstrably harmful. Among the questions this book seeks to answer are “What is the cost to theenvironment of raising so many food animals?” and “What is the cost to ourbodies of eating them?” We also ask “What is the cost to the animals?” Ifan animal is treated well, can exhibit its natural behaviors, and has a quickand painless death, then killing and eating it is easier to justify. However,most food animals are not so lucky. Hogs’ tails and chickens’ beaks are par-tially cut off. Egg-laying hens are squeezed into small cages. Broiler chick-ens spend their entire short lives in sheds crammed with tens of thousandsof birds, never getting a glimpse of the outdoors or pecking for insects inthe ground. Steers are often branded with hot irons, and bulls are castrated
  16. 16. • Six Arguments for a Greener Dietwithout sedatives. Animal welfare activists have documented egregiousexamples of mistreatment of animals prior to slaughter, with chickensbeing smashed against walls and cattle having their throats slit and beinghung by their legs without first being rendered unconscious. In this era of global warming, researchers have cited the overall energyand pollution costs of different diets as an important reason to eat lessmeat. University of Chicago geophysicists Gidon Eshel and Pamela Mar-tin calculate that it takes about 500 calories of fossil-fuel energy inputs toproduce 100 calories’ worth of chicken or milk; producing 100 calories’worth of grain-fed beef requires almost 1,600 calories. But producing 100calories’ worth of plant foods requires only 50 calories from fossil fuels.In terms of global warming, eating a typical American diet instead of anall-plant diet has a greater impact than driving a Toyota Camry instead ofa gas-frugal Toyota Prius.1 And that difference translates into an annual430 million tons of carbon dioxide, 6 percent of the nation’s total emis-sions of greenhouse gases. Nutrition researchers in Germany have examined the ecological impactsof three kinds of diets: typical Western, low meat, and lacto-ovo vegetarian.2Compared to a typical diet, a low-meat diet uses 41 percent less energy andgenerates 37 percent less carbon dioxide equivalents (greenhouse gases)and 50 percent less sulfur dioxide equivalents (respiratory problems, acid Greenhouse Gases Global warming is occurring because increased amounts of carbon dioxide and other gases in the atmosphere trap extra heat and gradually warm our planet. While automobiles and fossil-fuel power plants are the biggest contributors to global warming, agriculture also plays a role.  Livestock (mostly cattle) plus the manure lagoons on factory farms (mostly hog) generate an amount of methane that promotes about as much global warming as the release of carbon dioxide from 33 million automobiles. Methane is 23 times as potent as an equal amount of carbon dioxide.  Nitrous oxide—which comes from degradation of manure and from fertilizer applied to cropland—is 300 times as potent as carbon dioxide in promoting global warming and accounts for 6 percent of the greenhouse effect in the lower atmosphere.  Manufacturing fertilizer generates both carbon dioxide and nitrogen-containing greenhouse gases.
  17. 17. Preface: Greener Diets for a Healthier World • xirain). For a lacto-ovo vegetarian diet, the savings are even greater: 54 per-cent less energy, 52 percent less carbon dioxide equivalents, and 66 percentless sulfur dioxide equivalents. Eating less meat and dairy products could greatly improve health,the environment, and animal welfare—especially if people replaced someof those foods with vegetables, beans, fruits, nuts, and whole grains (see“Changing Your Own Diet,” p. 143). Most minimally processed plant foodsare low in saturated fat and cholesterol and high in vitamins, minerals, anddietary fiber, and they are the only source of diverse phytonutrients. Whileproducing more grains, vegetables, and fruits would require land, water,pesticides, and fertilizers, the amounts used would be small compared tothe amounts saved by producing less animal-based foods. Even withoutcutting back on beef and dairy foods, just shifting the cattle industry awayfrom feedlots and toward leaner grass-fed beef and getting the dairy indus-try to cut the saturated-fat content of milk would yield big dividends. This pro-plant message, however, has one important caveat: Animalproducts do not have a monopoly on causing harm. Diets rich in salt, par-tially hydrogenated vegetable oils (with their trans fat), refined sugars, andrefined flour also cause major health problems—heart disease, strokes, obe- Different gases have stronger or weaker effects on pollution. It is customary to convertthem into equivalents of carbon dioxide and sulfur dioxide so their effects may be comparedor combined.
  18. 18. xii • Six Arguments for a Greener Diet sity, and tooth decay, to name a few. And certain crops—such as sugar cane in Florida and, indeed, almost any row crop grown in monoculture on large farms—wreak serious environmental damage. While moving in a more vegetarian direction offers many benefits to health and the environment, a more omnivorous option is advo- cated eloquently by Universityof California journalism professor Michael Pollan in his recent book, TheOmnivore’s Dilemma. Pollan describes the multiple virtues of small farmsthat humanely and ecologically raise cattle, pigs, and chickens on pasturesand in woodlands and sell their meat, milk, and eggs locally.3 There’s littleroom for factory farms, Wal-Marts, or Burger Kings in that vision, thoughthe consumption of animal products could be at unhealthy levels. A more (ortotally) plant-based diet could be as compatible with sustainable agricultureas diets that include animal products, but comparing the two approachesis a good reminder that no path is perfect: Each has its own compromisesrelated to taste, cost, convenience, cultural values, health, ecology, animalwelfare, and the vitality of rural America. Ultimately, what you eat is yourchoice. Despite the well-recognized benefits of diets higher in healthy plant-based foods and lower in animal products (especially those produced onfactory farms), relatively few people will change their diets (and few farm-ers will change their growing practices) without encouragement from newgovernment policies. Six Arguments, therefore, suggests a range of policyoptions and programs (see “Changing Government Policies,” p. 151). Someof our proposals would directly promote a healthier, more environmentallysound diet. Others might reduce consumption by increasing the price ofanimal products. And some would improve the lives of farm animals. That’s what Six Arguments for a Greener Diet is about. Now a few words aboutwhat it is not about. Six Arguments focuses on the United States, though thesame logic applies to every other nation. The United States and other indus-trialized nations have largely passed through the “nutrition transition,”meaning that diets that were once based largely on starchy grains and pota-
  19. 19. Preface: Greener Diets for a Healthier World • xiiitoes now include much greater amounts of meat. Hundreds of millions ofpeople in India, China, Indonesia, and other developing nations are follow-ing our footsteps toward the meat counter. As Lester Brown, president ofthe Earth Policy Institute and a long-time analyst of global agriculture poli-cies, has noted, the animal-rich American diet requires the production offour times as much grain per person as the average Indian diet.4 If the entireworld’s population were to eat as much meat as Westerners, two-thirds moreland would be needed than is currently farmed.5 The increased demandfor water, fertilizer, and pesticides and the concomitant increased pollutionwould be unsustainable and ultimately devastating to our planet. Six Arguments for a Greener Diet puts the health, environmental, andanimal welfare consequences of raising and eating livestock under themicroscope, but does not delve into the whys and wherefores of the situ-ation. Why are so many animals allowed to be raised in miserable condi-tions? Why are restaurants permitted to market fatty hamburgers and otherunhealthy foods to young children? Why are livestock operations that raisethousands or tens of thousands of chickens, pigs, and cattle allowed to pollutewaterways and the atmosphere with tons of smelly, drug-tainted manureand global-warming pollutants? Why are huge soybean and grain farmsallowed to use such large amounts of fertilizer and pesticides that the run-off pollutes rivers, lakes, and even oceans? Why do farmers who grow cropsto feed livestock receive billions of dollars in annual subsidies, hundreds
  20. 20. xiv • Six Arguments for a Greener Dietof times as much as fruit andvegetable growers receive? Whydoes the federal government notshape its farm and health policiesaround its sensible Dietary Guide-lines for Americans and the vitalityof rural communities? It’s questions like those thatactivate dozens of agribusiness,food industry, environmental,health, and consumer groupsat the local, state, and nationallevels. The answers to the “why”questions are matters of politics,not science, and typically revolvearound money and livelihoods.The makers of pesticides, fertil-izer, and animal drugs; the cattle,hog, poultry, and dairy indus-tries; the large grain companiesand grain farmers—they all defend the status quo. They pour millionsof dollars each year into campaign contributions, lobbyists’ salaries, andadvertising campaigns. They wine and dine politicians—often over fattysteaks—and use hardball tactics to rein in any rare elected official who daresstray from the proper path. (Senators will long remember how, in 1980, thecattle industry successfully campaigned to defeat South Dakota senatorGeorge McGovern because he dared recommend that people eat less beef.)And, by making use of the “revolving door,” top officials from the cattle,pork, dairy, and other food- and agriculture-related industries become topofficials in the U.S. Department of Agriculture, and many former legislatorsand Department of Agriculture officials enjoy more lucrative, and no lessinfluential, careers on Washington’s K Street, where they lobby for thoseindustries. Getting the “why” questions answered in a way that protects humans,animals, and the environment will require the involvement of thousands ofconcerned citizens, nonprofit organizations, concerned farmers and com-panies, legislators, and government officials at the local, state, and nationallevels. Considering how important these matters are, now is the time tostart. Meanwhile, each of us can quietly do our part—in our kitchens, gro-cery stores, farmers’ markets, and backyard gardens.
  21. 21. The Context
  22. 22. The Fatted SteerG rain-fed beef. Since the 1950s, that term has conjured up thoughts of tender, juicy, delicious meat. Grain-fed beef is advertised by super- markets and featured by restaurants. Omaha Steaks, a nationalretail and mail order company, pro-claims: “We select the finest grain-fed  Grain-fed beef is rich in saturatedbeef for superior marbling, flavor and fat and cholesterol, which promotetenderness.” Morton’s, the high-end heart disease.steakhouse chain, “serves only the  Growing corn and other crops for cat-finest USDA prime-aged, Midwest tle feed requires enormous amountsgrain-fed beef.” And the latest epicu- of fertilizer, water, pesticides, land,rean delicacy, Kobe beef—advertised and fossil the “most flavorful and tender  Feedlot cattle eat a grain-rich dietbeef on the Planet”—is fed grain (and that can cause digestive, hoof, andoften beer). The implication is that 1 liver diseases and necessitates the continuous feeding of antibiotics.beef from cattle that were not grain-fed is tough, tasteless, and simply not  Grass-fed cattle are less harmful to the environment and provide leanerworth eating. beef, but still generate air pollution. In truth, grain-fed beef, which Any kind of beef increases the risk ofaccounts for some 85 percent of colon cancer.American beef, epitomizes much of
  23. 23. • Six Arguments for a Greener Dietwhat is wrong with both the American “factory” approach to livestockproduction and the American diet. They eat a diet that sickens them. Theygenerate air and water pollution. They pack on fattier meat. And, to top itoff, grain-fed beef doesn’t necessarily taste better than grass-fed beef. A sensible argument for raising cattle and other ruminants is that theirmanure fertilizes grasslands, and they can convert into meat or milk thenutrient- and fiber-rich plant matter—grasses, cornstalks, and the like—thathumans cannot digest. Raising cattle that way, though not without prob-lems of its own, expands the food supply. However, in the United States,that rationale for including beef in the diet is undercut by the fact that thegreat majority of beef cattle spend months in feedlots eating grain, gettingfat, and generating pollution. The Objective: Cheap and Tender BeefRestaurateur and former professional football player Dave Shula’s “Viewson Great Beef” include the note that “A great steak is all about flavorful, juicyand tender beef.”2 And an animal physiologist with the U.S. Department ofAgriculture (USDA), discussing why he studies cattle proteins and genes,explains that “Tenderness is the most important trait to consumers.”3 The cattle industry certainly wants to satisfy consumers’ desires—andmaximize its profits. Fortunately for the industry, techniques that producetasty meat also turn out to be the cheapest way to raise cattle. The high-energy diets dished out at feedlots speed the animals’ growth, with much ofthe increased weight taking the form of fat. Much like a restaurant that triesto “turn” its tables as quickly as possible, the faster growth rate gets the cattleto market sooner. So with both gastronomic and financial motives in place,cattle producers have adopted practices that yield a very fatted steer indeed. Choosing to Produce Lean or Fatty BeefFor thousands of years, farmers have employed such factors as breeding andfeed to shape the nature and yield of the meat (or milk or pork or chicken). Inrecent decades, scientists and agribusiness firms have turned the art of meatproduction into a science, with careful research supplanting happenstance. Unfortunately, the practices that lead to the fastest production andcheapest prices are not what’s best for the consumer’s health.They Are What Their Parents AreBreed is a major determinant of cattle’s fat content. Angus, Hereford, andcrosses with other breeds are the most popular breeds in the United States,not least because they are among the fattiest. They have the largest amounts
  24. 24. The Fatted Steer • Quality and Yield: Understanding USDA Meat Grades Because fat content is important to beef purchasers, the U.S. Department of Agri- culture has established a complex grading system that gives high grades to beef that is well-marbled with intramuscular fat.4 About 80 percent of all beef cattle and cows are graded by visual inspection at the slaughterhouse. The fattiest meat (8 percent marbling or higher) rates as Prime, the next fattiest (5 to 7 percent marbling) as Choice, and the leanest meat (3 to 4 percent marbling) as Select. In recent years, about 40 percent of cattle were graded as Select, 60 percent as Choice, and 2 to 3 percent as Prime.5 Restaurants and supermarkets pay a pre- mium for that fatty Prime meat. Producers also receive a premium for such special USDA grading programs as “Certified Angus Beef” or “Certified Hereford Beef,” which are breeds that yield mostly high-Choice beef (see figure 1).6 “External” fat—that is, fat outside of the edible beef used as steaks—is reflected in USDA’s “yield grades.” The lower the grade on a scale of 1 to 5, the less fat.7 Of meat that is graded, 85 percent is USDA yield grade 2 or 3. Although some producers argue that the quantity of external fat is unimportant because most of it is trimmed from beef cuts, much of that fat eventually ends up back in the food supply when it is blended with lean ground beef or used as shortening in baked goods.8 An even leaner grade of beef, Standard, represents only 0.3 percent of all meat that is graded.of external fat and the highest marbling scores, and they provide the high-est percentages of Choice meat (see figure 1). The Limousin and Chianinabreeds are far leaner. In Italy, in fact, the Chianina breed is prized for itslean meat. In the United States, it is often crossbred with other cattle—suchas the Hereford—to increase marbling in the Chianina or decrease back fatin the Hereford.They Are What They EatWhat cattle are fed greatly influences how fatty their meat will be. In a studyat Ontario’s University of Guelph, Ira Mandell and his colleagues let Limou-sin calves graze for eight months.9 The cattle were then fed either grain ormostly alfalfa hay for seven months (see table 1). The average carcass weightof the grain-fed steers was 45 pounds more than that of the hay-fed steers,reflecting faster growth on a high-energy diet. The layer of back fat over thelongissimus muscle (the main muscle in rib and strip loin cuts) was twice asthick in the grain-fed steers. And meat from the grain-fed steers containedalmost twice as much intramuscular fat. The hay-fed steers, on the otherhand, produced more lean meat than their grain-fed counterparts.
  25. 25. • Six Arguments for a Greener Diet Figure 1. Percentage of fattier meat in selected cattle breeds10 USDA Choice (% of meat) 80 70 60 50 40 Hereford-Angus 30 Maine Anjou Simmental Shorthorn 20 Charolais Limousin Gelbvieh Chianina Salers 10 0 Breed Notes: All carcass weights were about 700 pounds. While some breeds are inherently higher in fat, they will be leaner ifthey graze on pasture. In a study conducted at North Carolina State Uni-versity, Angus steers were kept on pasture or fed corn until they weighedabout 1,200 pounds (see table 2).11 The grass-fed steers took about 1½ monthslonger to reach that weight, and their meat contained much less fat marblingthan that from the grain-fed steers: Grass-fed beef was on the lean side ofUSDA Select, while grain-fed beef was on the high side of USDA Choice.Although the average carcass weight of the grass-fed steers was 75 poundsless than that of the grain-fed steers, the area of their longissimus musclewas almost as large as that of the grain-fed steers—a sign that grass-fedcattle can yield almost as much edible meat as grain-fed cattle. Moreover, Table 1. Carcass traits of Limousin steers fed grain or hay for 209 days12 Carcass trait Grain-fed steers Grass-fed steers Carcass weight 720 lb 674 lb Total fat 27% 19% Intramuscular fat 4.0% 2.7% Back fat over longissimus muscle at slaughter 0.4 in 0.2 in Lean meat 395 lb 409 lb
  26. 26. The Fatted Steer • Table 2. Carcass traits of Angus steers fed grain or grass and slaughtered at similar weights13 Carcass trait Grain-fed steers Grass-fed steers Days on diet 91 133 Weight at beginning of experiment 896 lb 909 lb Slaughter weight 1,260 lb 1,190 lb Carcass weight 750 lb 675 lb Marbling score* 6.2 4.5 USDA quality grade† 17.5 15 USDA yield grade ‡ 3 2.2 Longissimus muscle area 13.1 sq in 11.9 sq in * Scoring system designed by researchers to match USDA’s scoring system: 4 = slight degree of marbling; 5 = small; 6 = modest; 7 = high. † Scoring system designed by researchers to match USDA’s scoring system: 16 = Select; 17 = Choice; 18 = High Choice. ‡ Yield grade is measured on a scale of 1 to 5, with 5 containing the highest amount of waste fat.the lower yield grade indicates that the grass-fed beef had less low-valueexternal fat. An animal’s diet can override the effect of breed. Feeding grain to aleaner breed of cattle over longer periods can result in meat that is as fattyas that produced by a fattier breed. The University of Guelph researcherscompared the Red Angus breed with the leaner Simmental.14 Both groupsof animals were finished with a high-grain diet and slaughtered when theyreached the same back-fat thickness (about 0.4 inches, determined by ultra-sound). The Simmental took about 2½ months longer than the Red Angusto reach the same amount of back fat and, thus, spent substantially moretime on feed grains. The Simmental outweighed the Red Angus at slaugh-ter by 45 pounds, and, despite its “lean” reputation, had a slightly highermarbling score and total (external and internal) fat content. So, just becausemeat comes from a normally lean breed does not automatically mean thatthe meat is lean.Younger Is LeanerThe age at which cattle are slaughtered strongly affects fat content. In astudy led by Susan Duckett at the Oklahoma State University Meat Lab-oratory, grain-fed Hereford-Angus cattle were slaughtered after 28-dayintervals on high-energy diets.15 After periods longer than 84 days, cattleprogressively accumulated wasteful, external fat without increases in thepalatability (taste, juiciness, and tenderness) of their meat. Between 84 and
  27. 27. • Six Arguments for a Greener Diet112 days on feed grains, the cattle experienced the largest increase in exter-nal fat and marbling. During that period, the content of intramuscular fatmore than doubled, moving the meat from USDA Select to Choice. Thoseresults suggest that limiting grain feeding to 84 days—many cattle are onfeed for up to 190 days—could provide much more healthful meat. Fatty Meat Clogs Arteries…Fattening cattle on grain is the quickest way to get them to market, but thehigher fat content of feedlot beef is life threatening. Beef is a major source ofsaturated fat and cholesterol, which increase levels of the harmful kind ofcholesterol in our blood. That clogs arteries and increases the risk of heartattacks, the nation’s number-one cause of death. While consumers can eas-ily cut away the outside fat on steaks, they can’t remove the fat that marblessteaks or the fat in hamburgers and meatloaf. Grass-fed beef is usually lower in fat and less conducive to heart dis-ease.16 But, as we will discover in the next chapter, any kind of beef—espe-cially processed meats such as sausages—promotes colon cancer. …And Doesn’t Necessarily Taste BetterAmericans have been trained to salivate at the mention of grain-fed beef.“This creates well-marbled, tender, flavorful steaks. Marbling is the easiestway to spot a high quality steak,” says Iowa Corn Fed, a mail-order com-pany that charges as much as $35 a pound for a steak.17 One study foundthat pasture-raised beef sometimes has a “grassy” off-flavor. A Univer-sity of Nebraska study found that half the taste testers preferred corn-fedbeef, but the other half either preferred Argentinian grass-fed beef or wereundecided.18 Taste experts agree that corn-fed beef tastes different from grass-fedbeef, but not necessarily better. Corby Kummer, food editor for the Atlan-tic Monthly, says “Grass-fed beef tastes better than corn-fed beef: meatier,purer, far less fatty, the way we imagine beef tasted before feedlots andfarm subsidies changed ranchers and cattle.”19 Careful, moist cooking, suchas using marinades, helps reduce any stringiness. Many studies dispute Kummer, presumably because taste is subjec-tive and tasters bring with them their expectations of what tastes good.20But some of the studies make a case for grass-fed beef. Mandell and hiscolleagues at the University of Guelph compared meat from the popularHereford breed and the leaner Simmental breed. Cattle of each breed werefed mostly grass or mostly grain. A trained taste panel judged meat fromboth breeds—whether they ate grain or grass—to be equally palatable.21
  28. 28. The Fatted Steer • Another study—spon-sored in part by the NationalCattlemen’s Beef Association—found that among top loin, topsirloin, and top round steaks,consumers showed barelyany preference for the fattierChoice grade over Select.22The study, conducted by TexasAM University researchers,found that the more oftenconsumers purchased leanermeat, the less able they wereto distinguish among qualitygrades. They concluded thatthe “USDA quality grade maybe limited” in indicating thetaste of a steak. Taste is moreculturally determined thangenetically determined. It’s nosurprise, then, that people prefer the kinds of beef they grew up with: fattygrain-fed in the United States and lean grass-fed in Argentina (the biggestbeef-consuming country in the world). But we suspect that many more con-sumers would enjoy grass-fed beef if they both tasted it and were told of itshealth and environmental advantages. Although beef production is geared to delivering fattier Choice orPrime meat, some health-conscious consumers are seeking leaner meat.Some companies, such as Laura’s Lean Beef, pay ranchers a premium forcattle that yield leaner Select grade beef. Other ranchers, such as Maver-ick Ranch and Coleman, market grass-fed or organic beef, which is oftenleaner than regular beef, and are getting a premium for it. For example,Hawthorne Valley Farms, which boasts several hundred acres of lush pas-tureland, charges up to $20 per pound for grass-fed tenderloin steaks atlocal farmers’ markets.23 In response to this growing consumer demand,even the Cattlemen’s Beef Board sometimes highlights the low fat contentof certain steaks.24 Raising Cattle Harms the Environment…Raising tens of millions of cattle not only provides meat that promotesheart disease and sometimes causes food poisoning (see Arguments #1
  29. 29. 10 • Six Arguments for a Greener Diet Grass-Fed Beef: Better, but Not a Health Food Grass-fed beef is typically leaner than feedlot beef, a major advantage; and graz- ing on pasture spares the need for about 5,000 pounds of grain per animal. Beyond that, some advocates maintain that grass-fed beef is rich in two special kinds of fat—conjugated linoleic acid (CLA) and omega-3 fatty acids—that confer health benefits. One purveyor, Ameri- can Grass Fed Beef, emphasizes that its “grass fed beef is high in heart friendly essential fatty acids.”25 As yet, however, the evidence for such benefits is scanty, and even lean beef modestly increases the risk of heart disease and promotes colon cancer. Conjugated Linoleic Acid In the early 1980s, scientists suggested that CLA in beef might help fight obesity and prevent cancer. However, studies over the past two decades generally have been unsuccessful in linking the consumption of grass-fed beef to those “near- magical” (as one skeptical scientist stated) results.  Weight gain. Michael Pariza—the University of Wisconsin scientist who first iden- tified CLA in beef and heralded its possible benefits—found that CLA reduces weight gain in laboratory mice, with possibly smaller benefits in other lab ani- mals.26 However, Pariza notes that the fat mostly reduces future weight gain, not the initial weight. An industry-sponsored study suggests that CLA might lower the percentage of body fat, but not weight.27 An added complexity is that meat and dairy products contain one form of CLA, while dietary supplements contain an additional form. Only the form in supplements affects weight in animals. The bottom line is that human studies have not shown a benefit,28 and some research indicates that supplements may increase the risk of diabetes, heart disease, and other problems.29 In 2002, the Institute of Medicine, a part of theand #2), but also wreaks environmental havoc, as detailed in Arguments #3,#4, and #5. A mid-sized feedlot with 10,000 cattle churns out half a millionpounds of manure each day—equivalent to a city such as Washington, D.C.,with 500,000 residents. That mountain of fragrant manure pollutes the airand sometimes pollutes streams and rivers, killing plants and animals. Themethane that cattle and their manure produce has a global-warming effectequal to that of 33 million automobiles.
  30. 30. The Fatted Steer • 11 National Academy of Sciences, stated that “research on the effects of CLA on body composition in humans has provided conflicting results” and declined to set a recommended intake level.30 Overweight individuals should run—but not to grocery stores for grass-fed beef or drug stores for supplements.  Cancer. When female rats predisposed to mammary (breast) tumors were fed a diet containing 0.5 percent to 1 percent CLA, existing tumors grew more slowly or stopped growing, and fewer new tumors developed. Also, the tumors did not spread to other organs.31 In 1989, USA Today opined that beef “aids [the] war on cancer” and could “be made into a drug” if CLA proved beneficial to humans.32 But the Institute of Medicine threw cold water on that notion, too, saying that “to date, there are insufficient data in humans to recommend a level of CLA at which beneficial health effects may occur.”33 Even if beef’s CLA turns out to protect against cancer, grass-fed beef’s lower fat content—its real health advan- tage—would reduce the benefits from the higher content of CLA in its fat.34 Overall, the evidence that CLA offers health benefits is skimpy. And if CLA ever were proven to offer benefits, doctors certainly would prescribe pills, not burgers. Omega-3 Fatty Acids Some people claim that grass-fed beef is especially healthful because it contains about five times as much omega-3 fatty acids as grain-fed beef.35 Those are the same fatty acids—eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)—that are found in fish oil and appear to prevent heart attacks and possibly strokes.36 Beef also contains small amounts of alpha-linolenic acid, some of which the body can convert to EPA and DHA.37 But the amounts of all of those fatty acids are small. The American Heart Association recommends that people without heart disease eat fish twice a week, as well as flaxseed, canola, and soybean oils. People with heart disease should consume about 1 gram of EPA and DHA per day.38 To get that amount from grass-fed beef would mean eating about 5 to 10 pounds of rib steaks.39 Clearly, fish and dietary supplements are better sources: Three ounces of bluefin tuna provide 1.5 grams of the fatty acids; 3 ounces of Atlantic salmon provide 1.9 grams.40 Feeding grain to cattle makes a bad situation worse. It takes about7 pounds of corn to put on 1 pound of weight. That’s why over 200 millionacres of land are devoted to producing grains, oilseeds, pasture, and hay forlivestock.41 Moreover, cultivation of those crops requires 181 million poundsof pesticides, 22 billion pounds of fertilizer, and 17 trillion gallons of irriga-tion water per year. The fertilizer and pesticides pollute the air, water, andsoil, while irrigation depletes natural aquifers built up over millennia.
  31. 31. 12 • Six Arguments for a Greener Diet Grazing’s Pluses and Minuses Grazing is better in many ways than feeding grain to cattle, but it still exacts environmental costs. Cattle that eat grass and roughage release more methane (a gas that causes global warming and is 23 times more potent than carbon dioxide) than cattle on a high-energy feedlot diet, because grass-fed cattle take about 10 to 20 percent longer to reach market weight.42 Those longer lives also mean more manure—about 3,500 to 5,000 pounds per animal (60 pounds per day). That manure, though, is dispersed widely on pastureland, enriching the soil and nour- ishing the growth of plant life.43 …And the Cattle, TooOne measure of our humanity is how well we treat animals. While pets,of course, are often pampered almost like children, livestock are anotherstory. Aside from sometimes being branded with a burning hot iron and,in the case of males, castrated without the benefit of sedation or painkill-ers, beef cattle have a pretty good life for their first year or so, living on therange. But then virtually all cattle are shipped in crowded trucks—exposedto the elements and banged about—to feedlots, where they dwell for up tosix months in manure-befouled pens and eat a high-energy corn-based dietthat sometimes causes liver, hoof, and gastrointestinal illnesses and occa-sionally even fatal bloating. (Shipping the animals to the feed is cheaperthan hauling the feed to them. Indeed, in the case of chickens, corn and soy-bean meal account for 60 percent of the cost of production.44) When they’ve reached market weight, feedlot cattle (along with smallnumbers of pasture-raised cattle) are shipped for the final time to a slaugh-terhouse where they have a small, but real, risk of a slow, painful death.From that point on, the cattle exact a sort of posthumous revenge: First tosuffer are the workers in slaughterhouses and meat processing plants whoexperience everything from repetitive movement injuries to knife wounds.Next are the unwitting consumers, who may suffer foodborne illness in theshort term or fatal heart attacks in the long term. What It All MeansRaising cattle provides valuable nutrients, leather, and by-products used bythe food and drug and other industries. But considering how most cattleare raised, those positives are outweighed by a host of negatives. To protectour own health and our country’s environment, the best thing we coulddo would be to eat less, leaner, or no beef. Should that happen on a largeenough scale, vast areas of cropland could be freed up, allowing the land to
  32. 32. The Fatted Steer • 13regain much of its original fertility and biodiversity or to be planted in morehealthful fruit and vegetable crops or crops that would provide biofuel. But as long as people do eat beef, raising cattle on pastureland—insteadof feeding them grain—would dramatically reduce the fat content of beef,the waste and pollution of water and the fouling of air caused by manureand agricultural chemicals, and the misery experienced by the cattle con-signed to feedlots.
  33. 33. The Arguments
  34. 34. Argument #1.Less Chronic Disease and BetterOverall Health Our Diet Is Killing UsAt least one of every six deaths in the United States—upwards of 340,000each year—is linked to a poor diet and sedentary lifestyle.1 The averageAmerican is about as likely to diefrom a disease related to diet and  The saturated fat and cholesterol inphysical inactivity as from smoking beef, pork, dairy foods, poultry, andtobacco—and far likelier to die from eggs cause about 63,000 fatal heartdiet and inactivity than from an auto- attacks accident, homicide, or infec-  Less than a quarter of all adults eattious disease such as pneumonia.2 the recommended number of dailyAmong nonsmokers, the combina- servings of fruits and vegetables—tion of diet and physical inactivity is foods that reduce the risk of heart disease and cancer.the single largest cause of death. The specific diet-related diseases  Vegetarians enjoy lower levels of blood cholesterol, less obesity,that fell so many of us include heart less hypertension, and fewer otherdisease, certain cancers, stroke, and problems than people whose dietdiabetes. Those and other chronic dis- includes meat.eases (so called because they develop 17
  35. 35. 18 • Six Arguments for a Greener Dietand progress over many years) are caused in part by diets too poor inhealthy plant-based foods and too rich in unhealthy animal-based foods.We Eat Too Much of What’s Bad for Us…Obesity, which is directly linked todiet and a sedentary lifestyle, mark-edly increases a person’s risk of heartdisease, hypertension (high bloodpressure), diabetes, and some cancers.Rates of obesity have doubled in chil-dren and adults and tripled in teen-agers since the late 1970s, which is notsurprising, since—thanks to ubiqui-tous high-calorie foods—the average adult eats 100 to 500 calories more perday and—thanks to modern conveniences—exercises less.3 The additionalcalories have come mainly from the least healthy foods: white flour, addedfats and oils, and refined sugars.4 Moreover, Americans are eating more flesh foods—beef, pork, chicken,turkey, and seafood. In 2003, for instance, Americans ate more of each ofthose foods than they did a half-century earlier (see figure 1 and table 1).Fortunately, the biggest increase was for poultry, which is not directly linkedto chronic disease. However, a lot of that chicken—and fish too—is notbaked or grilled, but deep fried in partially hydrogenated oil. That oil con- tains trans fat, one of the most potent Figure 1. Major sources of animal causes of heart disease. Meanwhile, protein produced in the United Americans cut their consumption of States5 beef by 33 percent since 1976; that is likely due both to health concerns Eggs and lower chicken prices. 1.4 billion Pork Our inconsistent efforts to eat Poultry 2.3 healthy diets extend to non-meat 5.8 billion foods as well. Although we are eat- billion ing one-third fewer eggs—the yolks Beef 3.3 of which are our biggest source of billion cholesterol and thus contribute to Milk 5.6 heart disease—than we did in 1953, billion we are eating four times as much cheese—which is high in saturated fat and promotes heart disease (see 18.4 billion pounds per year table 1).
  36. 36. Argument #1. Less Chronic Disease and Better Overall Health • 19 Table 1. Per capita availability of major sources of meat, poultry, and seafood; dairy foods; and eggs6 al ve sh sh sh yo ilk n se y ke lfi rt ke ee el Fi gu ef k r ic gs M a r r Ch Ch Be Tu Po Ye Eg 1909 56 41 10 1 10* 34 4 293 1953 61 39 15 4 11 37 7 379 1976 92 41 29 7 13 30 16 270 2003 62 49 58 14 16 23 31 253 Notes: Figures for meat, poultry, and seafood represent the numbers of trimmed (edible) pounds per capita that were available in the food supply; the remaining figures represent the per capita numbers of gallons (milk and yogurt), pounds (cheese), or eggs that were available in the food supply. Due to waste and spoilage, actual consumption is lower. Beef consumption peaked in 1976. *Figure is for 1929, the first year for which data are available. Looking at other non-animal-derived portions of our diet, we are con-suming massive amounts of nutritionally poor plant-based foods, notably: refined grains (white bread, white pasta, and white rice), which are stripped of much of their nutrients and dietary fiber; soft drinks and other foods high in refined sugars (including high- fructose corn syrup), which replace more healthful foods and promote obesity; and baked goods and fried foods made with partially hydrogenated vege- table oil and palm, palm kernel, and coconut oils, which promote heart disease.Finally, there’s salt. The large amounts of salt in most packaged and restau-rant foods and processed meats increase blood pressure, which increasesthe risk of heart attacks and strokes.…And Not Enough Whole Grains,Fruits, and VegetablesThe U.S. Department of Agriculture(USDA) estimates that the average adulteats only one serving of whole grainsdaily.7 In contrast, the Dietary Guide-lines for Americans recommends thatat least half of our 6 to 10 daily grainservings should be whole grain.8 The
  37. 37. 20 • Six Arguments for a Greener Diet The Cardiovascular Benefit of Eating Less Meat and Dairy Probably the biggest health benefit from eating less animal products (other than fish) is a lower risk of heart disease. The Center for Science in the Public Interest estimated the approximate benefit based on the:  amounts of different fatty acids and cholesterol that are supplied by various animal products,  impact of saturated fat and cholesterol on blood cholesterol levels, and  relationship between blood cholesterol and heart disease. We first estimated how our consumption of fats and cholesterol would change if all the beef, pork, milk and cheese, poultry, and eggs were removed from the average diet and either not replaced or replaced with foods that did not affect the risk of heart disease.9 Next, we projected how those changes in fat and cholesterol intake would affect blood cholesterol levels by averaging the results from formulas devel- oped by several leading researchers.10 We then assumed that a 1 percent increase in blood cholesterol—total or low-density lipoprotein (LDL, or “bad” cholesterol) increases heart disease mortality by 2 percent.11 Those calculations indicate that avoiding animal fats 5,000 deaths would save about 63,000 lives per year (see figure).12 Because Eggs that estimate is based on inex- Beef 16,000 deaths act assumptions, the true total 19,000 Dairy might easily be 25,000 more deaths Poultry 5,000 or fewer lives per year. The deaths number of lives saved would be dramatically greater if one Pork assumed that people replaced much of the meat and dairy 18,000 deaths products with healthier plant- The fat and cholesterol in meat, dairy, based foods or fish. The eco- poultry, and egg products cause about nomic benefit of avoiding the 63,000 deaths from heart disease each year. fat would be about $100 billion a year or in excess of $1 trillion over 20 years.13 On the other hand, the same methodology indicates that the healthy unsaturated fats in salad oils currently save about 7,000 lives a year. Of course, we could reap some of those benefits by switching to lower-fat ani- mal products—such as from beef to chicken or even buffalo and to low-fat dairy foods.
  38. 38. Argument #1. Less Chronic Disease and Better Overall Health • 21 The Economic Benefits of a More Plant-Based Diet Diseases related to a diet too poor in plant foods and too rich in animal foods contribute to skyrocketing health-care costs. The annual cost of angioplasties and coronary bypass operations is about $50 billion, with statin heart-disease drugs adding $15 billion.14 Spending to treat high blood pressure (including $15 billion for drugs15), stroke, diabetes (another $7 billion for drugs), and cancer add additional billions.16 And, of course, on top of the medical costs are the incalculable amounts of pain and suffering (of both the people with the diseases and their friends and relatives) and lost productivity. Eating a more plant-based diet wouldn’t eliminate all those costs, but would cer- tainly move us well along in the right direction. One study estimated that going vegetarian would save the nation $39 billion to $84 billion annually.17 If obesity— which is much less common in vegetarians than others—were eliminated, we could save about $73 billion a year.18USDA also estimates that we are eating 1.2 servings of fruit and 3.7 serv-ings of vegetables per day, considerably less than the recommended 5 to 10daily servings.19 And, disappointingly, potato chips and French fries (whichare often cooked in partially hydrogenated shortening) here count as “veg-etables.” Indeed, one-third of the vegetables that we eat are iceberg lettuceand potatoes, two of the least nutritious. We are consuming only one-thirdthe recommended amount of the most nutritious vegetables: deep yellowand dark leafy green vegetables, and beans.20 According to the USDA, we’re very slowly increasing our consump-tion of vegetables: Fresh vegetables are up 33 percent, and total vegetablesare up 25 percent, since 1970. Surprisingly, though, fruit consumption is uponly 12 percent over that period and has not increased at all in 20 years.21 As our diets have been buffeted by cultural, economic, and other fac-tors, the evidence that certain dietary changes can reduce our risk of chronicdisease has become much stronger. Much of the research shows that peoplewho eat more plant-based diets, such as those traditionally eaten in Medi-terranean or Asian countries, are generally healthier than those eating thetypical American, Canadian, or northern European diet. How Do We Know?Study after study points to meat and dairy products, especially fatty ones,as causes of chronic diseases. The harm results both from specific constit-uents in animal products (such as saturated fat and cholesterol) and frompushing healthier nutrient-rich plant foods out of the diet. This section
  39. 39. 22 • Six Arguments for a Greener Dietpresents the science behind the (by now) commonly accepted premise thateating too many of the wrong animal products and too few of the healthiestplant foods does tremendous harm to our health. Again, a common-sensecaveat: Modest amounts of fatty fish and low-fat dairy, meat, and poultryproducts—even an occasional hot dog or cheeseburger—certainly can fitinto a healthy diet. The problems arise from immoderation. One approach to understanding the influence of diet on health is tocompare groups of people who eat very different diets. Such “observational”studies can provide important insights into what constitutes a health-promoting diet, though they cannot determine with certainty the particularelements in the diets—or other aspects of the subjects’ lives—that areresponsible for the better health. We review those studies first, then examine“intervention” studies, which are better able to identify causes and effects.Finally, we examine the health effects of specific foods and nutrients.Observational Studies Show That Vegetarians Live Longer and AreLess Prone to Chronic DiseasesStudies that compare disease patterns in people with different kinds ofdiets help identify factors that cause or prevent diseases. For example, dif- ferences in disease rates between veg- etarians (or vegans, who abstain from all animal products, including dairy and eggs) and non-vege- tarians can help iden- tify the effects of meat and other animal products. The weak- ness of this “observa- tional” approach is that factors other than diet—such as physical activity, air pollution, use of legal and illegalMeatless meals offer an incredible variety of tastes, textures, and drugs, and cigarettesmells. smoking—affect dis-ease rates as well. Scientists try to account for those kinds of factors, but it isimpossible to know about and account for everything.
  40. 40. Argument #1. Less Chronic Disease and Better Overall Health • 23Seventh-day Adventists Eat a More Plant-Based Diet and Live Longer andHealthier LivesSeventh-day Adventists (SDAs), whose religion advocates abstinence frommeat and poultry as well as alcohol and tobacco, have provided invalu-able evidence on lifestyle and health.22 About half of American SDAs fol-low a vegetarian diet or eat meat less than once a week. About one-quarterof SDAs follow a meatless lacto-ovo vegetarian diet, which includes dairyproducts and eggs, and about 3 percent are vegan. Generally, even non-veg-etarian SDAs eat less meat than does the average American. Vegetarian ornot, SDAs also tend to be physically active and eschew tobacco and alco-hol. So, by comparing vegetarian and non-vegetarian SDAs and adjustingfor factors such as smoking, physical activity, and alcohol, the effects of avegetarian diet can be teased out. Vegetarian SDAs may also be comparedto the general population to shed light on the health effects of a lacto-ovovegetarian diet. SDAs, on average, consume less saturated fat and cholesterol and moredietary fiber than the average American.23 They eat more fruit, green salads,whole wheat bread, and margarine and less meat, cream, coffee, butter, andwhite bread. The same is true of vegetarian SDAs compared to non-vegetar-ian SDAs.24 Key findings from studies of SDAs include the following: Longevity. Vegetarian SDA women live 2.5 years longer than non- vegetarian SDA women; vegetarian SDA men live 3.2 years longer than their non-vegetarian counterparts.25 Heart attacks. Non-vegetarian SDA men have twice the rate of fatal heart attacks as vegetarian SDA men.26 Similarly, the risk of fatal heart disease is more than twice as high for men who eat beef more than three times a week as for vegetarians.27 However, beef consumption or vegetarianism does not clearly affect the risk of heart disease in women.28 Stroke. SDAs in the Netherlands have about a 45 percent lower death rate from strokes than the total Dutch population.29 Cholesterol. Among African American SDAs, LDL (“bad”) cholesterol and triglycerides (the most common fat found in blood) were lower in vegans than in lacto-ovo vegetarians.30 Both of those fatty substances promote heart attacks. Hypertension. Hypertension, which increases the risk of heart attacks and strokes, is twice as common in non-vegetarian SDAs as in vegetar- ians; semi-vegetarians (those who eat fish and poultry less than once a week) had intermediate rates.31 Those findings apply to both men and women. When hypertension was defined as “taking antihypertensive
  41. 41. 24 • Six Arguments for a Greener Diet medication” (those with more severe hypertension), non-vegetarians had almost three times the rate of hypertension as vegetarians.32 Diabetes. Diabetes is twice as common in non-vegetarian SDAs, whether male or female, as in vegetarians, with semi-vegetarians having an inter- mediate prevalence.33 Cancer. Prostate cancer is 54 percent, and colon cancer is 88 percent, more common in non-vegetarian than in vegetarian SDAs.34 Some of those health benefits may be due not to particular nutrients inplant foods, but to the fact that bulky plant-based diets help reduce bodyweight. For example, for the average 5’10” male SDA, non-vegetarians weighan average of 14 pounds more than vegetarians. For 5’4” female SDAs, non-vegetarians weigh 12 pounds more than vegetarians.35Vegetarians Have Less Heart Disease, Hypertension, and DiabetesStudies of non-SDA vegetarians yield similar results. For example, the USDA’s1994–95 Continuing Survey of Food Intake by Individuals asked more than13,000 people whether they considered themselves to be vegetarian.36 Self-defined vegetarians whose diets did not include meat made up 0.9 percentof this nationally representative sample. Compared to non-vegetarians,the self-defined vegetarians tended to consume less fat, saturated fat, andcholesterol and more fiber. Self-defined vegetarians also ate more grains,legumes, vegetables, and fruit. In addition, they consumed fewer caloriesand had lower BMIs (body mass index, which combines height and weight)than non-vegetarians.37 Several large studies in Europe have examined the health of vegetar-ians. The European Prospective Investigation into Cancer and Nutrition(EPIC) is an ongoing study involving over 500,000 people in 10 countries.The part of that study being conducted in the United Kingdom (EPIC-Oxford) involves more than 34,000 non-vegetarians and close to 33,000non-meat-eaters (including people who eat fish, lacto-ovo vegetarians, andvegans).38 Another British study, the Oxford Vegetarian Study, compared6,000 vegetarians to 5,000 non-vegetarians.39 (More than half of the non-vegetarian subjects in that study did not eat meat daily and, therefore, werenot typical of the general British population.) Findings from those studiesand similar ones include the following: Cholesterol. Vegans have 28 percent lower LDL cholesterol levels than meat-eaters. Lacto-ovo vegetarians and fish-eaters have levels between those of vegans and meat-eaters.40 Based on blood cholesterol levels, the researchers estimated that heart disease rates would be 24 percent lower
  42. 42. Argument #1. Less Chronic Disease and Better Overall Health • 25 in lifelong vegetarians and 57 percent lower in lifelong vegans than in meat-eaters. Heart disease. Vegetarians have a 28 percent lower death rate from heart disease than meat-eaters.41 Blood pressure. Vegetarians have lower blood pressure and a lower rate of hypertension than non-vegetarians. Vegans have the lowest blood pres- sure and the least hypertension, followed by vegetarians and fish-eat- ers; non-vegetarians have the highest rates of hypertension.42 (Differ- ences in body weight were responsible for about half of the variation in blood pressure; alcohol consumption and vigorous exercise accounted for some of the variation in men.43) The EPIC-Oxford study found hyper- tension rates of 9 percent in lacto-ovo vegetarians and 13 percent in non-vegetarians.44 Diabetes. Mortality from diabetes is markedly lower for vegetarians (and for health-conscious non-vegetarians) than for the general population.45 As with the SDAs, some of the European vegetarians’ health advan-tages are likely due to lower rates of obesity.46 For instance, in the OxfordVegetarian Study, overweight or obesity (BMI 25) was twice as common innon-vegetarian men, and 1½ times more common in non-vegetarian women,as in vegetarians.47 In a Swedish study of middle-aged women, the risk ofobesity was 65 percent lower in vegans, 46 percent lower in lacto-vegetar-ians (those who avoid meat, fish, poultry, and eggs), and 48 percent lowerin semi-vegetarians compared to non-vegetarians.48 On average, vegetar-ians are leaner than their non-vegetarian counterparts by about 1 BMI unit Meta-Analysis Find Vegetarians Have Less Heart Disease Meta-analysis is a powerful statistical technique that combines the results from a number of similar studies into a single, large analysis. If done properly, such an analysis can provide more conclusive results than any single study. A meta-analysis of five studies (the Adventist Mortality Study, Health Food Shoppers Study, Adven- tist Health Study, Heidelberg Study, and Oxford Vegetarian Study) included a total of 76,172 vegetarians (both lacto-ovo vegetarians and vegans) and non-vegetarians with similar lifestyles.49 The vegetarians had a 24 percent lower rate of fatal heart attacks than non-vegetarians. When compared to people who ate meat at least weekly, mortality from heart disease was 20 percent lower in occasional meat- eaters, 34 percent lower in those who ate fish but not meat, 34 percent lower in lacto-ovo vegetarians, and 26 percent lower in vegans. (The data on vegans may not be reliable, because the meta-analysis included only 753 vegans.) The meta- analysis did not find any difference in death rates from stroke or cancer between the vegetarians and non-vegetarians.
  43. 43. 26 • Six Arguments for a Greener Diet(roughly 6 pounds).50 Differences in rates of obesity and BMI may be due tovegetarians’ higher intake of fiber and lower intake of animal fat, althoughother unknown factors also appear to be involved.51 In sum, several large studies have found that vegetarians enjoy lowerrisks of major chronic diseases and longer lives than non-vegetarians. Thatis not surprising, considering that vegetarians have lower rates of obesity,lower saturated fat and cholesterol intakes, higher fiber intakes, and lowertotal and LDL cholesterol levels. Vegetarians’ somewhat greater physicalactivity also plays a role. Smoking clearly is an important risk factor, butmost recent studies adjust for it, as well as for age, alcohol use, and otherreadily identified factors. It is always possible, of course, that vegetariansmay differ from other people in ways not accounted for in the studies. Though the numbers of vegans in the studies are small, they tendto have lower serum total and LDL cholesterol, less hypertension, and alower prevalence of obesity than lacto-ovo vegetarians. However, thereis no evidence that vegans live longer than lacto-ovo vegetarians andsemi-vegetarians.52Followers of a “Prudent” Diet Are Less Likely to Have Heart DiseaseOther major studies have found important connections between dietarypatterns and heart disease. The ongoing Nurses’ Health Study, which ismanaged by the Harvard School of Public Health, compared a “prudent”diet, with higher intakes of fruits, vegetables, legumes, whole grains, fish,and poultry, to the “Western” pattern, which is high in red and processed(sausage, bacon, and the like) meats, sweets, desserts, fried foods, and refinedgrains. After 12 years, among the more than 69,000 participants, the womenwho ate prudent diets were 36 percent less likely to develop heart diseasethan those who ate typical Western diets.53 In a similar study of almost 45,000male health professionals, a prudent diet was associated with about a 30 per-cent lower risk of developing heart disease or of dying from a heart attack.54Intervention Studies Demonstrate Benefits of Low-Fat Vegetarian DietsThe bottom line from observational studies is that diets based more on plantfoods—and that means carrots, not carrot cake—pay big health dividends.But the limitation of those studies is that vegetarians and other health-conscious individuals might be doing things besides eating more plantfoods and fewer animal products that are the real reasons for their betterhealth. Intervention studies overcome that limitation. The best way to study the effect of diet on chronic disease is to assignparticipants randomly to two or more different diets. Such “intervention”
  44. 44. Argument #1. Less Chronic Disease and Better Overall Health • 27studies include those in which subjects were placed on vegetarian or otherkinds of diets, thus allowing researchers to evaluate the diets’ relativestrengths and weaknesses.Low-Fat Vegetarian Diets Can Lower Blood Pressure and Decrease theRisk of Heart DiseaseVegetarian diets have proven to be remarkably beneficial for people whohave cardiovascular disease. For instance, switching from ordinary omniv-orous diets to a lacto-ovo vegetarian diet with similar sodium content butmore fiber, calcium, and potassium reduced the blood pressure in subjectswho had either normal or high blood pressure.55 Differences in the kinds offat, as well as the levels of minerals, in the vegetarian and non-vegetariandiets may have accounted for some of the differences in blood pressure.56 Several recent intervention studies examined the effect of a near-vegandiet high in phytosterols and soluble fiber on blood cholesterol levels.57Phytosterols are plant-based substances with a chemical structure related tocholesterol; they are added to some margarines, yogurts, and orange juice toreduce cholesterol absorption. The soluble fiber in such foods as oats, barley,psyllium, eggplant, and okra forms thick, sticky solutions that increase theexcretion from the body of bile acids and lower blood cholesterol levels. David Jenkins and colleagues at the University of Toronto placed peoplewith high blood cholesterol levels on either (1) a near-vegan diet high inphytosterols, soluble fiber, and soy protein; (2) a low-saturated-fat lacto-ovovegetarian diet; or (3) the latter diet along with a cholesterol-lowering statindrug. The diet that included phytosterols, soluble fiber, and soy proteinimproved cholesterol levels just as much as the lacto-ovo vegetarian dietplus the statin. Judging fromthe subjects’ changes in cho-lesterol levels, blood pressure,and other measures, the near-vegan diet led to a 32 percentlower risk of heart diseasethan the lacto-ovo vegetariandiet. The near-vegan diet pre-sumably had a greater effectbecause of the soluble fiber,phytosterols, and possibly soyprotein (but see “Soy Foods:No Health Miracle,” on p. 39). Morale-boosting communal dinners likely contribute to theJenkins notes, “There is hope success of the CHIP heart-health program (see next page).
  45. 45. 28 • Six Arguments for a Greener Dietthat these diets may provide a non-pharmacologic treatment option forselected individuals at increased risk of cardiovascular disease.”58 Based in part on the Toronto studies, the National Cholesterol Educa-tion Program, a part of the National Heart, Lung, and Blood Institute, rec-ommended a combination of statins and dietary modifications for patientswith high LDL cholesterol levels (above 130 milligrams per deciliter).59 Hans Diehl, a health educator at the Lifestyle Medical Institute inLoma Linda, California, has developed a community-based CoronaryHealth Improvement Project (CHIP) that involves hundreds of people ata time. CHIP encourages participants to switch to a near-vegan, low-fatdiet (though most participants make more modest changes) and engagein walking or other physical activities.60 After only a few weeks on the The DASH and Mediterranean Diets The Dietary Approaches to Stop Hypertension (DASH) intervention study used a more plant-based, but not vegetarian, diet. DASH examined the effects of a diet that includes twice the average daily consumption of fruits, vegetables, and low- fat dairy products; one-third the usual intake of red meat; half the typical use of fats, oils, and salad dressings; and one-quarter the typical number of unhealthy snacks and sweets. It emphasizes whole grains and severely limits salt (see “Chang- ing Your Own Diet,” p. 143, for more about this diet). Compared to a typical Ameri- can diet, the DASH diet lowers blood cholesterol, blood pressure, and the risk of cardiovascular disease.61 A major strength of this study was that the subjects were given all their meals, so the researchers knew exactly what they were eating. A prominent French study, the Lyon Diet Heart Study, tested the effect on heart disease of a Mediterranean-type diet that emphasizes fruits, vegetables, bread and other grains, potatoes, beans, nuts, seeds, and olive oil and contains only modest amounts of animal products. In subjects who had already had a heart attack, the Mediterranean diet led to 50 to 70 percent fewer deaths, strokes, and other complications compared to those following a “prudent” Western-type diet.62 Interestingly, blood cholesterol levels and cigarette use were similar in the two groups, indicating that other factors—possibly the threefold higher level of alpha- linolenic acid, an omega-3 fatty acid, in the experimental group—play important health roles. Also, weight loss was not responsible for the dramatic benefit—a finding unlike those in some other studies. Harvard Medical School professor Alex- ander Leaf commented that this “well-conducted” study showed that “relatively simple dietary changes achieved greater reductions in risk of all-cause and coro- nary heart disease mortality in a secondary prevention trial than any of the cho- lesterol-lowering [drug] studies to date.”63 He also noted that the subjects readily adhered to this diet.
  46. 46. Argument #1. Less Chronic Disease and Better Overall Health • 29program, participants typically eat more fruits and vegetables and lesssaturated fat and cholesterol than a control group. In one study, comparedto the controls, the participants’ average LDL cholesterol level declined by14 percent.64 Subjects who changed their diets also lost an average of 7½pounds, and their rate of hypertension dropped in half. The CHIP studyshows that a health-promotion program can provide enormous benefits tolarge groups of people in a cost-effective way.Diet and Exercise Can Reverse Heart DiseaseDean Ornish, of the University of California in San Francisco, and his col-leagues have done ground-breaking studies in patients with moderate tosevere heart disease. The researchers prescribe a very-low-fat vegetariandiet (containing no animal products except nonfat dairy products and eggwhites), along with moderate aerobic exercise, smoking cessation, and stressreduction. That regimen significantlyimproved cholesterol levels, at least Fighting Prostate Cancertemporarily. It also began unclogging with Lifestylearteries and preventing angina (thechest pain that occurs when the heart Prostate cancer, which kills 30,000muscle does not get enough blood) American men each year, may beand heart attacks. Lipid-lowering 65 controlled with lifestyle changes,statin drugs were not needed. The including a low-fat vegan diet. Dean Ornish and his colleagues at the Uni-lifestyle changes were as effective as versity of California “treated” withcoronary bypass surgery in reducing diet, fish oil and other supplements,angina. The subjects who ate the low- exercise, and other lifestyle changesfat vegetarian diet and made other half of a group of 93 volunteers withlifestyle changes lost an average of early prostate cancer. The other24 pounds, which was undoubtedly half received the usual care. Afteran important factor in their improved one year, prostate-specific anti-health. gen, one index of prostate cancer, In another study by Ornish’s decreased 4 percent in the treat-research group, 440 men and women ment group but increased 6 percentwith coronary artery disease ate in the control group. The cancerthe same largely vegetarian diet progressed sufficiently in six men inand made the prescribed lifestyle the control group, but in none in thechanges. After one year, the subjects 66 experimental group, to warrant con-enjoyed reduced blood lipids (13 per- ventional medical therapy.67cent lower LDL cholesterol in men,16 percent lower in women), blood pressure (1 to 2 percent reduction in sys-tolic blood pressure), and weight (5 percent in men, 7 percent in women).
  47. 47. 30 • Six Arguments for a Greener Diet In a smaller but much longer study, Caldwell Esselstyn of the Cleve- land Clinic monitored 18 patients with severe coronary artery disease.68 Most of them had suf- fered coronary problems after a previous bypass surgery or angioplasty.Decades of eating fatty meat and dairy products can turn healthyarteries (like the opened and flattened human aorta at left) into All of those who ate anones afflicted with severe atherosclerosis (right). almost entirely plant-based diet had no recurrence of coronary events over 12 years (a few patientstook low doses of statin drugs some of the time). One patient who “fell offthe wagon” had a heart attack and then resumed the program. The coronaryarteries of 70 percent of the patients studied became less clogged. In Dr. Es-selstyn’s words, his patients had become “virtually heart-attack proof.” One concern about diets high in carbohydrates is that they tend to raisetriglycerides and lower high-density lipoprotein (HDL, or “good” choles-terol), a prescription for heart disease. However, in China and Japan, wheretraditional diets are very high in carbohydrates, heart disease is almostnonexistent. That’s probably because most Chinese and Japanese peoplehave been lean and active—very different from the typical American. Inaddition, studies by Dean Ornish and David Jenkins of North Americansare reassuring. They found that diets high in carbohydrates from wholegrains and beans, but low in white flour and sugar, led to major reduc-tions in LDL cholesterol but had little or no effect on triglycerides and HDLcholesterol. The fact that Ornish’s subjects were moderately active and lostweight undoubtedly helped. Ornish speculates that even when high-carbo-hydrate diets lower HDL cholesterol, that does not increase the risk of heartdisease, while the low HDL cholesterol levels seen in people whose dietsare high in refined sugars and starches do promote heart disease.69A More Plant-Based Diet Can Treat Type 2 DiabetesLow-fat vegetarian diets can treat type 2 diabetes, a terrible and increas-ingly common disease that causes everything from blindness to gangrene(and amputations) to heart disease. In one 26-day study of 652 people withdiabetes, more than one-third of the insulin-using subjects who adopted alow-fat vegetarian diet were able to discontinue the insulin. Close to three-quarters of those on the vegetarian diet who were taking oral hypoglycemic
  48. 48. Argument #1. Less Chronic Disease and Better Overall Health • 31medicines were able to stop taking them.70 The vegetarian diet also yieldeda 22 percent reduction in serum cholesterol and a 33 percent reduction intriglycerides. Some of those benefits were likely due to the subjects’ losingan average of 8 pounds. A study that combined a low-fat, high-fiber vegan diet with dailyexercise and weight loss (11 pounds in 25 days) was also highly successfulin treating type 2 diabetes.71 The lifestyle changes eliminated the painrelated to diabetes-caused nerve damage in most of the subjects. It alsoreduced fasting blood glucose levels, blood pressure, and the need formedications. The results of intervention studies strongly indicate that a largely plant-based diet provides tremendous benefits—sometimes even as great as thoseachieved by powerful prescription drugs or surgery. Though some of thosestudies also involved relaxation, exercise, or low levels of drugs, diets con-sisting mostly of nutritious plant-based foods clearly are extremely effectiveat preventing or treating chronic diseases. The benefits include reductionsin blood pressure, total and LDL cholesterol, blood glucose, clogging ofarteries, and—most importantly—less cardiovascular disease and type 2diabetes. Building on that body of research, leading health agencies in the UnitedStates and abroad have developed quite similar dietary advice (see table 2).They stress the benefits from beans, whole grains, fruits, vegetables, andseafood, along with physical activity, and the harm that is associated withfatty meat and dairy products. What Specific Foods Should We Be Eating—and Avoiding?The studies we have discussed com-pared the health effects of widely dif-ferent diets. Researchers also havestudied the health benefits and risks ofspecific food groups, such as fruits andvegetables, and meat.Fruits and VegetablesAmericans are eating slightly morefruits and vegetables today than thepaltry amounts we ate 35 years ago,but still far less than the recommended5 to 10 servings per day. Fruits and